Demand from passengers on airplanes for multimedia services is on the rise, requiring airplanes to be wirelessly connected to terrestrial data sources or communication networks. Wireless broadband channels for transmitting data at very high data rates may be needed to connect airplanes to a satellite network for the transmission of multimedia data. For this purpose, antennas having small dimensions may be installed on airplanes so as to be installed beneath a radome, but nonetheless satisfy extreme requirements in regard to the sending characteristics for directional wireless data communication with the satellite (such as in the Ku, Ka or X band) because interference from neighboring satellites must be reliably precluded.
The antenna may be movable beneath the radome so as to track the orientation at the satellite when the airplane is moving. The antenna may be be lightweight so as to cause only little additional fuel consumption of the airplane.
The regulatory requirements in regard to sending operations are derived from international standards. These regulatory guidelines are intended to ensure that no interference of neighboring satellites can take place in the directional sending operation of a mobile antenna that is mounted on the airplane and sending to a satellite.
Approaches for compact antennas for aeronautical satellite communication are shown in WO 2014005693, for example, describing ridged horn antennas as single radiating elements. These single radiating elements are arranged in an antenna array and fed high-frequency signals via suitable feed networks. According to WO 2014005693, steps within the ridged horn antenna are used to improve matching of the ridged horn antenna to the free space. However, these steps may result in an increased height.
Alternative designs of single radiating elements are described in DE 3146273, DE 2152817 and U.S. Pat. No. 4,040,060, with corrugations being introduced into walls of a horn antenna so as to increase the bandwidth of the horn antenna. The corrugations are introduced successively in concentric rings into an edge of the horn antenna for this purpose. U.S. Pat. No. 4,897,663A shows a horn antenna comprising multiple corrugations (chokes), which may be suitable for optimizing the directivity of the single radiating elements for multiple frequencies. These measures may not reduce height.